US3975666A - Pneumatic and hydraulic control valves - Google Patents

Pneumatic and hydraulic control valves Download PDF

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Publication number
US3975666A
US3975666A US05/495,086 US49508674A US3975666A US 3975666 A US3975666 A US 3975666A US 49508674 A US49508674 A US 49508674A US 3975666 A US3975666 A US 3975666A
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US
United States
Prior art keywords
capacitor
storage means
circuit
coils
charged
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US05/495,086
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English (en)
Inventor
Robert J. Redding
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Skinner Precision Industries Inc
Original Assignee
Skinner Precision Industries Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to GB3731173A priority Critical patent/GB1466246A/en
Priority to SE7409474A priority patent/SE7409474L/xx
Priority to JP49088150A priority patent/JPS5070860A/ja
Application filed by Skinner Precision Industries Inc filed Critical Skinner Precision Industries Inc
Priority to US05/495,086 priority patent/US3975666A/en
Priority to DE2437952A priority patent/DE2437952A1/de
Priority to FR7427480A priority patent/FR2240553B1/fr
Priority to NL7410603A priority patent/NL7410603A/xx
Application granted granted Critical
Publication of US3975666A publication Critical patent/US3975666A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F7/00—Magnets
    • H01F7/06—Electromagnets; Actuators including electromagnets
    • H01F7/08—Electromagnets; Actuators including electromagnets with armatures
    • H01F7/18—Circuit arrangements for obtaining desired operating characteristics, e.g. for slow operation, for sequential energisation of windings, for high-speed energisation of windings
    • H01F7/1805—Circuit arrangements for holding the operation of electromagnets or for holding the armature in attracted position with reduced energising current
    • H01F7/1816—Circuit arrangements for holding the operation of electromagnets or for holding the armature in attracted position with reduced energising current making use of an energy accumulator
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H47/00—Circuit arrangements not adapted to a particular application of the relay and designed to obtain desired operating characteristics or to provide energising current
    • H01H47/22—Circuit arrangements not adapted to a particular application of the relay and designed to obtain desired operating characteristics or to provide energising current for supplying energising current for relay coil
    • H01H47/226—Circuit arrangements not adapted to a particular application of the relay and designed to obtain desired operating characteristics or to provide energising current for supplying energising current for relay coil for bistable relays

Definitions

  • This invention relates to circuits for causing operation of electromagnetically operated devices such as control valves for pneumatic and hydraulic circuits, for use in locations where there is a fire and/or explosion hazard.
  • the preferred method of safe-guarding electrical equipment in the presence of hazardous atmospheres is to make the electrical circuit intrinsically safe. This requires that the energy level in the circuit is at all times below a critical value, so that any sparks resulting therefrom are not of sufficient energy to ignite the atmosphere.
  • the circuit includes energy storage means which is charged from a source at an intrinsically safe energy level and is subsequently at least partially discharged via switching means through an operating coil of the electromagnetic device.
  • FIG. 1 is a circuit diagram showing one form of circuit in accordance with the invention together with a safety barrier, and
  • FIG. 2 is a circuit diagram of an alternative form of circuit in accordance with the invention.
  • the ratio of pull-in energy to hold-in energy may, for example, be 10 : 1.
  • a typical solenoid valve which operates a pilot may require a current of not less than 100 mA to pull in the solenoid, whereas a current of 10 or 20 mA may be quite adequate to hold it in.
  • FIG. 1 of the drawings An example of a circuit in accordance with the invention for causing operation of an electromagnetically operated device which requires a relatively high pull-in power and a lower hold-in power is shown in FIG. 1 of the drawings.
  • a safety barrier 1 such as a zener diode barrier circuit as described in my U.S. Patent No. 977,913, is connected between a d.c. source and a supply line 2 and 3 which is connected to the electromagnetic device via a switch 4.
  • the safety barrier 1 preferably comprises a network of resistors and zener diodes which are arranged to ensure that in spite of any occurrence on the safe side of the barrier, i.e. the lefthand side in FIG. 1, the power delivered to the lines 2 and 3 in a danger area will be intrinsically safe, provided that the lines 2 and 3 and any circuit 5 connected thereto does not have values of inductance and capacitance which exceed certain design values.
  • the circuit 5 comprises a capacitor 6 of, for example, several thousand ⁇ F capacitance, which is connected across the lines 2 and 3 via a diode 7 and a series resistor 8.
  • a series circuit comprising a zener diode 9 and a resistor 10 is connected across the capacitor 6, the junction between the resistor and capacitor being connected to the base electrode of a transistor 11.
  • An operating coil 12 of an electromagnetic device, such as a solenoid valve, is connected in series with the collector/emitter circuit of the transistor 11, across the capacitor 6.
  • the whole of the circuit 5 may be encapsulated.
  • the capacitor 6 starts to charge from the d.c. source via a resistor 8 and the diode 7.
  • the voltage across the capacitor 6 rises rapidly towards the no-load voltage of the power supply.
  • this diode is non-conductive and the voltage across the resistor 10 remains at zero.
  • the transistor 11 therefore remains biased-off so that no current flows through the coil 12.
  • the current fed to the coil 12 by this circuit is much higher than would be the case if the capacitor 6 were not present.
  • the circuit which in the absence of the capacitor 6 would produce perhaps only tens of mA for feeding the coil 12 can, by virtue of the capacitor 6, produce a current pulse of the order of 1A for operation of the solenoid.
  • the current available is not determined by the length of the leads connecting the circuit with the power source, since the capacitor 6, which is situated only a very short distance from the coil 12, acts as the source of pull-in current.
  • the encapsulation of the circuit 5 ensures intrinsic safety of the circuit, and the resistor 8 and the diode 7 ensure that no charge from the capacitor 6 passes back along the lines 2 and 3 where a dangerous spark could be caused.
  • a capacitor 6 is used in the above embodiment to act as a storage element
  • other devices such as electrolytic cells or even secondary cells of the nickel-cadmium type may be used for the purpose.
  • other types of semi-conductor switching devices or even mechanical relays may in some instances be used in place of the transistor 11.
  • the coil 12 is said to be the solenoid of a hydraulic valve, other forms of mechanically-operated devices may be energised in the same manner.
  • the storage element could transfer its charge into the coil 12 on receipt of a signal from another source.
  • the zener diode might be replaced by any other suitable voltage-sensitive device, such as a thermister.
  • the circuit shown in FIG. 2 is suitable for use with a known latching solenoid valve or other type of magnetic latching device of the kind which is switched on by one electrical pulse and is switched off by another pulse, no power from an electrical source being needed to hold-in the device.
  • the latching device has two coils 13 and 14 which are connected in series with a capacitor 15 and a thyristor 16 across d.c. supply lines 17 and 18 which are fed from lines 2 and 3 via resistor means 8 and diode 7 as in the previous embodiment.
  • a capacitor 19 is connected across the lines 17 and 18.
  • a series resistance/diode network is connected between the line 18 and the junction of the resistor 8 and the diode 7, the network comprising a diode 20, a zener diode 21 and a resistor 22.
  • a capacitor 23 is connected across the network.
  • the gate of the thyristor 16 is connected to the junction of the resistor 22 and the diode 21.
  • a transistor 24 is connected, via a collector resistor 25, across the coil 13 and the capacitor 15, the emitter of the transistor being connected to the line 17.
  • the base of the transistor 24 is connected via a resistor 26 to the junction between the diode 7 and the resistor 8.
  • a capacitor 27 is connected between the base and the emitter of the transistor 24.
  • the collector of the transistor 24 is connected to the gate of a thyristor 28, which is connected across the coil 13 and the capacitor 15.
  • a capacitor 29 is connected in parallel with the thyristor 28, and a capacitor 30 is connected in parallel with the thyristor 16.
  • the application of the 24v supply to the lines 2 and 3 charges the capacitor 19 through the resistor 8 and the diode 7.
  • the diode 21 begins to conduct, thereby passing current to the gate of the thyristor 16.
  • the thyristor 16 is triggered, and the capacitor 19 discharges through the capacitor 15 and the coils 13 and 14. The current pulse in these coils operates the valve.
  • a voltage is obtained across the capacitor 15 in the following manner.
  • the initial discharge of the capacitor 19 charges the capacitor 15 to approximately 10v, and the thyristor 16 turns off because current is no longer flowing through the zener diode 21.
  • the capacitor 19 recharges to approximately 22,5v, the thyristor 16 is triggered again, the capacitor 15 is charged to a higher voltage, the thyristor 16 turns off again, and the cycle is repeated several times until the capacitors 19 and 15 are both charged to approximately 22.5v.
  • the latter voltage is limited by the current flowing through the safety barrier (as in FIG. 1), the resistor 8, the diode 7, the zener diode 21 and the gate of the thyristor 16.
  • the capacitor 19 will discharge slowly through the resistor 26, this current being similar in magnitude to the internal leakage in the capacitor.
  • the capacitor 19 retains most of its charge for several minutes, which makes the next operation quicker than the initial one.
  • the capacitors 23, 27, 29 and 30 are small value capacitors which help to prevent the thyristors from being triggered spuriously.
  • valve remains in its present state in the event of a power supply failure.
  • the valve can be provided with means for unlatching it manually or automatically since sufficient energy is stored in the capacitor 15.
  • the circuit shown in FIG. 2 for pulsed magnetic latch operation can also be used for a valve which has a magnetic hold-on feature, e.g. by means of a permanent magent.
  • the valve requires a magnet "boost” or “buck” to operate “on” and "off” and this is provided if the single coil 13 is connected, no coil 14 being required in this instance.
  • the capacitors 6 in FIG. 1, and 19 and 15 in FIG, 2 are charged to a voltage approaching that of the intrinsically safe supply.
  • the safe supply could be stepped up to a higher voltage by means of an inverter located within the encapsulated circuit 5, between the diode 7 and the capacitors.

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Magnetically Actuated Valves (AREA)
  • Direct Current Feeding And Distribution (AREA)
US05/495,086 1974-07-02 1974-08-05 Pneumatic and hydraulic control valves Expired - Lifetime US3975666A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
GB3731173A GB1466246A (en) 1974-07-02 1974-07-02 Electrical switching circuits
SE7409474A SE7409474L (sv) 1974-07-02 1974-07-22 Elektrisk krets for styrning av funktionen for en elektromagnetiskt driven anordning
JP49088150A JPS5070860A (en, 2012) 1974-07-02 1974-08-02
US05/495,086 US3975666A (en) 1974-07-02 1974-08-05 Pneumatic and hydraulic control valves
DE2437952A DE2437952A1 (de) 1974-07-02 1974-08-07 Schaltkreis zur steuerung einer elektromagnetisch betaetigten einrichtung
FR7427480A FR2240553B1 (en, 2012) 1974-07-02 1974-08-07
NL7410603A NL7410603A (nl) 1974-07-02 1974-08-07 Elektrisch circuit.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB3731173A GB1466246A (en) 1974-07-02 1974-07-02 Electrical switching circuits
US05/495,086 US3975666A (en) 1974-07-02 1974-08-05 Pneumatic and hydraulic control valves

Publications (1)

Publication Number Publication Date
US3975666A true US3975666A (en) 1976-08-17

Family

ID=26263412

Family Applications (1)

Application Number Title Priority Date Filing Date
US05/495,086 Expired - Lifetime US3975666A (en) 1974-07-02 1974-08-05 Pneumatic and hydraulic control valves

Country Status (7)

Country Link
US (1) US3975666A (en, 2012)
JP (1) JPS5070860A (en, 2012)
DE (1) DE2437952A1 (en, 2012)
FR (1) FR2240553B1 (en, 2012)
GB (1) GB1466246A (en, 2012)
NL (1) NL7410603A (en, 2012)
SE (1) SE7409474L (en, 2012)

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4068283A (en) * 1976-10-01 1978-01-10 General Electric Company Circuit breaker solid state trip unit incorporating trip indicating circuit
US4128856A (en) * 1977-07-29 1978-12-05 Macleod Donald A Automatic resetting control circuit for air switch operator
EP0111016A1 (en) * 1981-10-14 1984-06-20 Oded E. Sturman Integrated latching actuators
EP0120258A1 (de) * 1983-02-25 1984-10-03 Siemens Aktiengesellschaft Energiesparschaltung
EP0122370A1 (en) * 1983-03-16 1984-10-24 International Business Machines Corporation Control circuit for a bistable relay
US4718454A (en) * 1985-11-20 1988-01-12 British Gas Plc Valve operating system
US4779839A (en) * 1986-11-28 1988-10-25 Sears Lawrence M System for actuating an electrical valve from a remote location
US4957273A (en) * 1986-11-28 1990-09-18 Sears Lawrence M Remote shut-off valve
USRE33825E (en) * 1983-03-16 1992-02-18 International Business Machines Corporation Sub-milliamp mechanical relay control
GB2363271A (en) * 2000-06-09 2001-12-12 Apollo Fire Detectors Ltd A fire door release circuit including a latching relay
GB2406980A (en) * 2003-10-10 2005-04-13 Dbt Autom Gmbh A fast solenoid valve operating on an intrinsically safe power supply in a mine
CN103016823A (zh) * 2012-12-08 2013-04-03 中国航天科技集团公司第六研究院第十一研究所 冗余控制快速释放电路
CN104455649A (zh) * 2014-09-29 2015-03-25 三一重型装备有限公司 本安比例电磁阀驱动模块、本安比例控制系统及矿用设备
CN105765237A (zh) * 2013-12-03 2016-07-13 费斯托股份有限两合公司 阀装置
EP3467864A4 (en) * 2016-06-01 2019-10-30 ZTE Corporation CIRCUIT AND METHOD FOR CONTROLLING SINGLE COIL MAGNETIC LOCK RELAY
EP3822993A1 (de) 2019-11-13 2021-05-19 Minimax Viking Research & Development GmbH Verfahren und vorrichtung zur elektrischen ansteuerung eines aktors

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2406884A1 (fr) * 1977-10-24 1979-05-18 Matsushita Electric Works Ltd Circuit de commande de relais bistable
US4305283A (en) * 1979-08-29 1981-12-15 Whessoe Limited Position determining apparatus
FR2498807A1 (fr) * 1981-01-23 1982-07-30 Socapex Relais monostable a faible consommation
EP0373870B1 (en) * 1988-12-13 1994-03-16 Seiko Epson Corporation Dot wire driving apparatus
DE8910048U1 (de) * 1989-08-22 1991-01-03 Siemens AG, 1000 Berlin und 8000 München An ein Wechselspannungsnetz anschaltbares elektromagnetisches Schaltgerät

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2427751A (en) * 1945-03-29 1947-09-23 Westinghouse Electric Corp Capacitor closed relay having reduced holding current
DE1117693B (de) * 1958-07-23 1961-11-23 Funke & Huster Elek Zitaets G Elektropneumatische, auf Steuerimpulse aus eigensicheren Stromkreisen ansprechende Steuervorrichtung fuer druckluftbetriebene Einrichtungen von Untertagebetrieben
US3121175A (en) * 1959-08-03 1964-02-11 Thomson Houston Comp Francaise Transistor having threshold switch effecting coupling and feedback effecting temperature compensation
US3221174A (en) * 1962-06-04 1965-11-30 Gen Motors Corp Timing circuit with means for selectively alternating the timing pulses
US3382417A (en) * 1965-07-30 1968-05-07 Bourns Inc Time delay relay device
US3454839A (en) * 1966-03-23 1969-07-08 Alex C Mcintosh Electronic switching circuit

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2427751A (en) * 1945-03-29 1947-09-23 Westinghouse Electric Corp Capacitor closed relay having reduced holding current
DE1117693B (de) * 1958-07-23 1961-11-23 Funke & Huster Elek Zitaets G Elektropneumatische, auf Steuerimpulse aus eigensicheren Stromkreisen ansprechende Steuervorrichtung fuer druckluftbetriebene Einrichtungen von Untertagebetrieben
US3121175A (en) * 1959-08-03 1964-02-11 Thomson Houston Comp Francaise Transistor having threshold switch effecting coupling and feedback effecting temperature compensation
US3221174A (en) * 1962-06-04 1965-11-30 Gen Motors Corp Timing circuit with means for selectively alternating the timing pulses
US3382417A (en) * 1965-07-30 1968-05-07 Bourns Inc Time delay relay device
US3454839A (en) * 1966-03-23 1969-07-08 Alex C Mcintosh Electronic switching circuit

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4068283A (en) * 1976-10-01 1978-01-10 General Electric Company Circuit breaker solid state trip unit incorporating trip indicating circuit
US4128856A (en) * 1977-07-29 1978-12-05 Macleod Donald A Automatic resetting control circuit for air switch operator
EP0111016A1 (en) * 1981-10-14 1984-06-20 Oded E. Sturman Integrated latching actuators
EP0120258A1 (de) * 1983-02-25 1984-10-03 Siemens Aktiengesellschaft Energiesparschaltung
EP0122370A1 (en) * 1983-03-16 1984-10-24 International Business Machines Corporation Control circuit for a bistable relay
USRE33825E (en) * 1983-03-16 1992-02-18 International Business Machines Corporation Sub-milliamp mechanical relay control
US4718454A (en) * 1985-11-20 1988-01-12 British Gas Plc Valve operating system
US4779839A (en) * 1986-11-28 1988-10-25 Sears Lawrence M System for actuating an electrical valve from a remote location
US4957273A (en) * 1986-11-28 1990-09-18 Sears Lawrence M Remote shut-off valve
GB2363271A (en) * 2000-06-09 2001-12-12 Apollo Fire Detectors Ltd A fire door release circuit including a latching relay
GB2406980A (en) * 2003-10-10 2005-04-13 Dbt Autom Gmbh A fast solenoid valve operating on an intrinsically safe power supply in a mine
US20050078428A1 (en) * 2003-10-10 2005-04-14 Dbt Automation Gmbh, Mining solenoid
GB2406980B (en) * 2003-10-10 2005-10-12 Dbt Autom Gmbh Mining electromagnet
US7239498B2 (en) 2003-10-10 2007-07-03 Dbt Gmbh Mining solenoid
CN100354534C (zh) * 2003-10-10 2007-12-12 Dbt有限公司 矿井电磁铁
CN103016823A (zh) * 2012-12-08 2013-04-03 中国航天科技集团公司第六研究院第十一研究所 冗余控制快速释放电路
CN105765237A (zh) * 2013-12-03 2016-07-13 费斯托股份有限两合公司 阀装置
CN105765237B (zh) * 2013-12-03 2017-08-08 费斯托股份有限两合公司 阀装置
CN104455649A (zh) * 2014-09-29 2015-03-25 三一重型装备有限公司 本安比例电磁阀驱动模块、本安比例控制系统及矿用设备
EP3467864A4 (en) * 2016-06-01 2019-10-30 ZTE Corporation CIRCUIT AND METHOD FOR CONTROLLING SINGLE COIL MAGNETIC LOCK RELAY
US10964501B2 (en) 2016-06-01 2021-03-30 Zte Corporation Single coil magnetic latching relay control circuit and method
EP3822993A1 (de) 2019-11-13 2021-05-19 Minimax Viking Research & Development GmbH Verfahren und vorrichtung zur elektrischen ansteuerung eines aktors
DE102019130601A1 (de) * 2019-11-13 2021-05-20 Minimax Viking Research & Development Gmbh Verfahren und Vorrichtung zur elektrischen Ansteuerung eines Aktors

Also Published As

Publication number Publication date
JPS5070860A (en, 2012) 1975-06-12
GB1466246A (en) 1977-03-02
SE7409474L (sv) 1975-02-10
NL7410603A (nl) 1975-02-11
DE2437952A1 (de) 1975-02-20
FR2240553A1 (en, 2012) 1975-03-07
FR2240553B1 (en, 2012) 1978-12-29

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